1. Antonaci and Sjaastad The Journal of Headache and Pain 2014, 15:8
http://www.thejournalofheadacheandpain.com/content/15/1/8
LETTER TO THE EDITOR Open Access
Hemicrania continua: towards a new
classification?
Fabio Antonaci1* and Ottar Sjaastad2
Abstract
Hemicrania continua (HC) was described and coined in 1984 by Sjaastad and Spierings. Later cases, carrying this
appellation, should conform to the original description. The proposed classification criteria (ICHD 3rd edition beta
version) for HC focus e.g. on localized, autonomic and “vascular” features. Such features do, however, not belong to
the core symptomatology of HC and should accordingly be removed. The genuine, original HC will then re-appear.
The headache that the new criteria refer to, has in an unfair and unjustified manner been given the designation HC.
A revision of the proposed criteria seems mandatory.
Keywords: Hemicrania continua; Headache classification
Findings
Hemicrania continua (HC) was described and coined in
1984 by Sjaastad and Spierings [1]. Naturally, later re-ported
cases, carrying this appellation, should conform
with the original description of this clinical constellation
of symptoms and signs. Otherwise, errors will be intro-duced,
and confusion will arise. The essence of this head-ache
is: 1. Unilaterality of the head pain (Hemicrania), and
without side alteration, at that. 2. Continuous head pain
(continua). 3. A generally moderate, but somewhat fluctu-ating
pain, the pain only rarely approaching a high inten-sity
level. Thus, most patients were able to work, even
when the pain was stronger than usual. The patients had
generally not contemplated suicide. Nocturnal awakenings
occurred, but generally only rarely and during exacerba-tions.
4. And then the most spectacular, single factor: the
effect of indomethacin, which is obligatory and absolute-generally
with small dosages, i.e. 50–75 mg per day (not
more) – In other words, patients who do not fulfill the
indomethacin criteria, are not candidates for this headache
category. It was already from the early phase evident that
there were two temporal patterns: a primary chronic form;
and another one with an initial, remitting pattern, that
could last for some time, but with time generally develop-ing
into a continuous form.
The first two cases [1] were the prototypes of Hemicrania
continua.—Throbbing was generally rarely present, appear-ing
only during exacerbations. Facial/ forehead sweating
and miosis are NOT parts of this picture. That these signs
are included in the new criteria (ICHD 3rd edition beta ver-sion)
[2] seems to be a misunderstanding. The same goes
for much of what is written under: “Description”. It also
concerns the restlessness. This should not be used as a cri-terion
in HC, as it is a typical feature of Cluster headache.
Therefore, the proposal that the criteria “2. a sense of rest-lessness
or agitation, or aggravation of the pain by move-ment”
may be sufficient (in absence of other autonomic
symptoms and signs) for the HC diagnosis seems to be an-other
misunderstanding. And then, fundamental changes
in the total concept of HC were brought on, after which
HC easily could be confounded with similar, but neverthe-less
essentially different headaches. The original clinical
structure of HC remains; the headache itself had not chan-ged.
That leaves only one possibility open: it was the clini-cians’
concept of reality that had changed; the essence of
HC had probably been tampered with. The changes that
were introduced, were so fundamental that the original
cases [1] no more fulfilled the original criteria. This situ-ation
is not acceptable.
What had happened? The development may seem to
be like this:
It was claimed that although indomethacin seemed to
play a role in HC treatment, the effect was not always ab-solute,
and it could even be entirely lacking [3]. And much
* Correspondence: fabio.antonaci@unipv.it
1Headache Centre, C. Mondino National Institute of Neurology Foundation,
IRCCS, Department of Brain and Behavioral Sciences, University of Pavia,
Pavia, Italy
Full list of author information is available at the end of the article
© 2014 Antonaci and Sjaastad; licensee Springer. This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly cited.

2. Antonaci and Sjaastad The Journal of Headache and Pain 2014, 15:8 Page 2 of 3
http://www.thejournalofheadacheandpain.com/content/15/1/8
larger doses might be needed to obtain effect. The propor-tion
of non-responders seemed to increase. In the end, a
series of non-responders was published: “Hemicrania con-tinua
is not that rare” [4,5]. It is self-evident that if strict
and pure criteria are conscientiously loosened, more pa-tients
will fit into this category. It was claimed that these
patients nevertheless had the “phenotype” of HC. This did
not stand to reason. Indomethacin response- absolute/
close to absolute- is a cornerstone in the diagnosis of HC.
We have no doubt whatsoever that cases like the de-scribed
ones exist. But they are not cases of HC. They
have little to do with HC. They are rather cases of what
we have termed: “Non-indomethacin responsive chronic
hemicrania” or: NIRCH [6,7]. This group is probably
larger than HC itself; it may even be much larger. This
category may even contain various sub-groups. Also for
that reason, this headache category should be given
another appellation. It may be a promising task for young
researchers to explore this field.
Actually, indomethacin mean requirement is generally
rather low, i.e. around 75 mg per day. During exacerba-tions,
the dosage may have to be enlarged to 100 or even
150 mg for a day or some days. Such periods should be
kept as short-lasting as possible, since indomethacin is a
potentially dangerous drug. It is, therefore, with great sur-prise
that one reads that the recommended dosages
should be “at least 150 mg daily and increased if necessary
up to 225 mg daily”. The recommended, initial test-dose
by “the Indotest” [8] is 50 mg intramuscularly. A dosage of
100 mg does not render any major advantage. The dosage
should NOT, as recommended by the committee, be
100–200 mg. With such dosages, one does not test the
specific qualities of indomethacin in this headache any
more then one tests general analgesic properties, and that
is not what one is searching. It would eventually give a
false indication of indomethacin effect and, in the long
term, such high dosages may even endanger the patient’s
life. The idea behind indomethacin therapy must be to try
to help the patient not to hurt him. This should be self-evident,
and the same reasoning is valid for CPH, where
similar dosages are recommended [2]. If high dosages are
being employed during the initial trial and during the ini-tial
period of therapy, many patients will develop intoler-ance
and side effects and eventually shy away from the
further use of indomethacin.
Somewhat later, it was proposed that “migrainous/ vas-cular
components” were integral parts of HC such as nau-sea/
vomiting and a pulsating quality of the pain. It may
also be noteworthy that in the description of this head-ache,
unilaterality is mentioned, but not whether it is side-locked
or not. This represents a further step away from
the HC-picture and a major one. Together, they will wipe
out the essence of the HC-picture. Vomiting may be an
insignificant -and rare- part of the HC exacerbation.
Vomiting does not belong to the core symptomatology of
HC. It may even, partially be a by-product of drugs. It
should also in this connection be pointed out that many
cases published under the category HC, sail under false
colors. Reviews and statistics based on such cases will not
render correct figures for the various variables. The vascu-lar
ingredient story is a most unwanted and unjustified
proposal that eventually might lead to a further alienation
from the genuine picture of HC.
The claim that facio-cephalic autonomic symptoms
can be part of the picture makes it utterly demanding to
recognize the original picture of HC. Forehead/facial
sweating is not part of the HC-picture. Nor is miosis. To
include them among the HC criteria is actually a consid-erable
blunder. Pupillary changes are, on the other hand,
a frequent accompaniment of NIRCH [6,7].
An indomethacin-responsive hemicrania, characterized
by continuous pain is most likely a case of HC, For head-aches
that do not fulfill the criteria of HC, one should
carefully try to re-categorize them or eventually find new
categories. Surprisingly, all the references to the original
work [9] are erased in the new edition of the criteria [2].
As already pointed out: these are the original, genuine cri-teria.
As for the HC type: remitting subtype (i.e. 3.4.1) [2],
as regards remissions, it is not a question of “at least one
day”. Remissions last for months to years. We have time
and again tried to emphasize these points of view, without
overwhelming response. However, “Gutta cavat lapidem,
non vi, sed saepe cadendo”.
The whole situation appears to be far from ideal. There
may seem to be two possible ways out of the present
predicament.
I. If this headache still is to be termed Hemicrania
continua in the new IHS version, the autonomic
features that do not belong to the core symptomatology
of HC should be removed, and so should the “vascular”
features. The genuine, original HC will then re-appear.
II. An appellation other than HC should be found for
the headache variant depicted in the new criteria.
The headache that these criteria refers to, has in an
unfair and unjustified manner been given the
designation HC. The presently depicted headache is
hardly a disorder in its own right, but rather a
mixture of various headaches, such as cluster
headache, CPH, and “vascular headache” and
NIRCH. In most of the cases, proper indomethacin
trials have not been carried out.
Competing interests
The authors declare that they have no competing interests.
Authors’ contributions
FA AND OS wrote the manuscript on the basis of the literature and on
personal experince in the field Both authors read and approved the final
manuscript.

3. Antonaci and Sjaastad The Journal of Headache and Pain 2014, 15:8 Page 3 of 3
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Author details
1Headache Centre, C. Mondino National Institute of Neurology Foundation,
IRCCS, Department of Brain and Behavioral Sciences, University of Pavia,
Pavia, Italy. 2Department of Neurology, St. Olavs Hospital, Trondheim
University Hospitals, NTNU, Trondheim, Norway.
Received: 26 December 2013 Accepted: 6 January 2014
Published: 13 February 2014
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doi:10.1186/1129-2377-15-8
Cite this article as: Antonaci and Sjaastad: Hemicrania continua: towards
a new classification?. The Journal of Headache and Pain 2014 15:8.
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